Addresses two questions that may be unique to perceptual learning: What are the circumstances that produce learning? and What is the content of learning? Suggests a critical principle for each question. Provides a discussion of perceptual learning theory, how learning occurs, and what gets learned. Includes a 121-item bibliography. (DR)

Notes young children's fast mapping ability for word and fact learning. Finds children's extension of a new word to novel objects from same category but lack of extension for new facts, as replicated by Waxman and Booth, unsurprising. Poses more interesting question: is word learning done solely through more general cognitive systems or through…